1. Field of the Invention
The present invention relates to cellular telephones and, more particularly, to a cellular phone speaker and microphone assembly that permits the use of cellular phones in a manner that limits the user""s exposure to electromagnetic radiation.
2. Description of the Related Art
Cellular telephones are handheld devices that are usually positioned immediately adjacent the ear and face of the user when in use. They operate by transmitting and receiving wireless signals to and from a remote cell site. As a consequence, they generate and receive electromagnetic radiation that can be harmful to individuals. In particular, when the cellular phone is transmitting to the cell site, electromagnetic radiation emits from the phone at a location adjacent the head of the user. It is believed that prolonged exposure to such electromagnetic radiation can pose health risks to the cellular phone user including increased incidence of brain tumors and cancer.
To address this concern, some microphone and speaker assemblies have been developed for the cellular phone to allow for the use of cellular phones without requiring the phone being placed immediately adjacent the user""s head. These assemblies typically involve attaching an electronic microphone and speaker by wire to the cellular phone in a manner so that only the speaker and microphone are adjacent the ear and mouth of the user while the cellular phone is being used. An electronic signal produced by the cellular phone is then transmitted along the electrical wire to the speaker and subsequently transformed into an audio signal by the speaker located adjacent the user""s ear. Furthermore, the electronic microphone that is positioned adjacent the user""s mouth converts audible voice signals produced by the user into electronic signals which in turn are transmitted via the wire to the cellular phone for subsequent transmission to the cell site.
While these speaker and microphone assemblies somewhat reduce the user""s exposure to electromagnetic radiation generated by the cellular phone, they still raise some health concerns as these assemblies themselves can be a source of electromagnetic radiation. In particular, these assemblies typically use an electrical conductor such as a metal wire to connect the speaker with the microphone and to transmit electronic signals to and from these devices. Disadvantageously, it is believed that the metal wire can act as an antenna which can receive and transmit electromagnetic radiation, thereby continuing to cause health risks to the cellular phone user.
To address these concerns, communication headsets that are configured to place all electronic components necessary for telephone communication remote from the user""s head have been developed. Specifically, U.S. Pat. No. 3,993,879 to Larkin discloses a headset assembly in which the microphone, receiver, and related amplifiers are housed in a detachable case that is worn on the user""s belt or lapel while hollow transmitter and receiver tubes are coupled to the case to conduct sound from the user""s mouth to the microphone and from the receiver to the user""s ear.
However, the Larkin reference places the microphone and speaker in such close proximity to each other inside the case such that undesirable noise interference between the two devices can occur. For instance, sound that is emitted from the receiver and intended for the user""s ear can be picked up by the microphone and retransmitted to the cell site, thereby create undesirable feedback. Similarly, sound generated by the user and intended for the microphone can reach the adjacent speaker and travel back to the user via the receiver tube next to the speaker. Disadvantageously, such sound wave interference generates extraneous noise that can adversely impact the clarity and overall quality of the communication. Furthermore, FIG. 2 of the Larkin reference illustrates that the case containing the microphone and speaker needs to be strapped to the user""s belt, which suggests that the case is not compact and light enough to hang freely from the tubes that are attached to the user""s head. Disadvantageously, it can be inconvenient and cumbersome for the user to have to attach such a case to the user""s belt or clothing whenever the cellular phone is in use.
Hence from the foregoing, it will be appreciated that there is a need for a cellular telephone assembly that will permit the use of the cellular phone in a manner that reduces the risk of exposure to electromagnetic radiation and yet does not compromise the clarity of sound transmission. Furthermore, it will be appreciated that there is a need for the cellular telephone assembly to be lightweight and not cumbersome so that users can use the cellular phone without having to attach any device or contraptions to the users"" clothing. To this end, there is a need for a cellular phone speaker and microphone assembly that is light, compact and configured to minimize noise interference between the speaker and microphone.
The aforementioned needs are satisfied by the cellular telephone speaker and microphone assembly of the present invention which permits the use of the cellular phone in a manner that reduces the user""s exposure to electromagnetic radiation and also minimizes noise interference between the speaker and the microphone.
In one aspect, the cellular phone speaker and microphone assembly of the present invention comprises a microphone and a speaker that are contained in a first and second enclosure respectively. The assembly further comprises a connecting member that is joined to the first and second enclosures in a manner such that the connecting member is interposed between the first and second enclosures to inhibit sound transmission between the microphone and speaker. Preferably, the connecting member interposes an air gap between the enclosures to inhibit transmission of sound therebetween. In one embodiment, the connecting member comprises a first and second circular disk, and a plurality of legs extending therebetween to separate the first and second disks by a first distance. Preferably, the first distance is approximately 0.2 inch.
In another aspect, the cellular phone speaker and microphone assembly of the present invention comprises a microphone and speaker that are each contained in a first and second enclosure respectively. The first enclosure has an upper opening that is adapted for transmitting sound from the user""s mouth to the microphone. The assembly further comprises an air tube that extends between the user""s ear and the second enclosure so as to transmit sound from the speaker to the user""s ear. In one embodiment, the first and second enclosures are adhered together.
In yet another aspect, the cellular phone assembly comprises a microphone and a speaker that are each contained in a first and second enclosure respectively. The first enclosure has a first cavity that is configured to seat and firmly hold the microphone inside the first enclosure and to channel substantially all sound entering an upper opening of the first enclosure to the microphone. Similarly, the second enclosure has a second cavity that is configured to seat and firmly hold the speaker inside the second enclosure and to channel substantially all sound from the speaker toward an upper opening in the second enclosure. Preferably, the first and second cavities are funnel shaped.
These and other objects and advantages of the present invention will become more fully apparent from the following description taken in conjunction with the accompanying drawings.